I am placing equipment inside my Skymaster Hawk which has a fair amount of carbon fibre in the airframe. I want to use a Revolution 1010 base loaded antenna but the question is: can I install it inside the fuse and away from CF reinforcing (I hate the way whip antennas look on jets)? Does CF cause dead spots if antenna is placed so that a CF caused shadow falls between antenna and transmitter?
Thanks for any help from the excellent knowledge base on this site.
Wayne - newbie to turbines

Carbon shorts out RADIO FREQUENCY to varying amounts.

Any good RC company should tell you the same.

If money is no object and you could not care less about failsafe lock ups on turns into people, Do what you want.

Carbon DOES NOT make a plane fly safer.

That is the stuff used in Stealth fighters. To make them stealthy.

There are several threads currently ongoing about this. Revloutions work extremely well. I use them in all my jets all of which have CF reinforcement.

Hi All,

What if we can install the whip antenna on the nose cone and make it look like a pitot type, this might look more scale. Does it have bad effect on the receptions?

Mike

i have a lot of carbon in my airworld katana t30 and the antenna lies inside the fuse i have never had any problems with that ,i don't know if it will change with a jet flying double the speed of my katana.

Wayne can u give me some nice info about the skymaster hawk , are you going to make a build threat here i am very interested in building one my self. how is the quality of the kit.

I have put yhe whole antenna in a carbon fuse and never had any problems. I use a Futaba MX 14

Chief, I am not posting a building thread. David Gladwin has written a limited article reviewing and building the Skymaster BAe Hawk. It was published in the April/May and June/July '05 issues of RC Jet International magazine. I ordered back issues of the mag and finally got them after waiting nearly a month.
Quality of my kit is pretty good. Two issues that cropped up are: 1) the flying stabs did not have the pivot/mounting bar in the same place on both halves, one elevator had the bar attached 3/8" closer to the elevator leading edge than other one and 2) the canopy mounting pins that hold the canopy to the front of the fuse were offset so the canopy didn't line up properly with the sides of the fuse. I had to fill the foles for the pins in the fuse and redrill them to get the canopy to line up properly. David mentions some other issued in his article, some of which my kit contained as well.
Hope this helps.
Wayne

Mike,
I would also like to use the Revolution antenna as a dummy "probe" but my layout won't allow this. My receiver is mounted to a Smart-Fly Powerexpander and is to large to place in the nose. The Rev antenna says to cut the receiver antenna 4" long before attaching but I would have to leave it 10". I have not tried this length but am pretty sure it will have a negative effect on range.

Thanks to everyone that posted advice here. I plan on mounting the Rev antenna in the front of the Hawk attached to the bottom of the fuse with goop. This will get a clear shot for the signal and away from CF, batteries, ECU and fuel pump. But I sure would like to mount it out the nose as the "pitot probe". I scaled the length of the Revolution antenna to the length of the real probe and it is within a 1/4" of correct length. Darn!

I have had several Carbon fusalage and i put the antena inside a nyrod inside the fuse.
and never had any problems.
Then again I only Futaba 14mz.

What is the length of the revolution antenna? You might consider mounting it inside along the curve of the plastic canopy, angled back from the instrument panel. Would be more 'vertical' than the lower front fuse, perhaps further from carbon fiber reinforcement, and not point at you when the aircraft flys directly towards the transmitter.

it all depends........cf being electrically conductive can pickup both rf and emf such as from a moter or ecu.....my worse case experience was with a siren hotliner with a cermark 800 bb...reciever was 5 chan hitec ppm/fm....with moter on range test was about 5 feet with ant running along bottom of all cf fuse.....simply unflyable....with ant out to top of rudder....30 ft.....oh trans was 14mz......a small pcm reciever helped but to this day the siren experiences lockouts/glitches etc....this is worse case scenario....all carbon fiber fusalage with an electrically noisy geared brushless moter pullin 60 amps.....bolted to the carbon fiber.......now on my jets besides mounting recievers/ecus/fuel pumps on non elect. conductive surface i try to avoid running ant. wire near any source of rf and avoiding running ant parallel with any long section of cf........so all your whip ant...base loaded i presume cause your cutting old ant to 4in length...is getting a section of ant with the whip into an rf "clean" position.......it does not matter if horizontal or verticle .....ouf rf links are not polarized......so if you hate the george jetson look of the whip as i do...can you route wire ant out to wing....like bvm bobcat...assuming no cf skin on wing...really ideal.....how about inside verticle fin....no cf ...ideal.....your power expander came with really long heavy guage leads....how about moving it with reciever to a better location....anyway just my ideas.....kp couch

That's weird...cause CF has been used by F1 (Formula 1) and CART for years for everything from structure to brakes...and the CF doesn't make them "stealthy"...it makes them STRONGER and LIGHTER.

i agree..cf is quite refractive of microwave energy contained in radar beam......cf doesnt make an a/c steathy....its angled surfaces and radar freq. coating on outer skin does....an a/c is said to be steathy if it doesnt provide a good radar signature....kpc

wayne..i just reread tour post and realized what you plan to do.....by mounting base loaded whip inside fuse you arent gaining anything over your original long wire ant that came with reciever.....you see antanna efficiency /or gain is measured in decible/dB.....say your original rec long wire ant for 72 mhz.....is natural fraction of wavelength....ie 1/4 wave....1dB gain.....1/2 wave....4 dB gain...full wave....16 dB gain...this shows gain as a function of wavelenght or lenght of ant is logrythmic...so say your original 1/8 wave ant measured 38 in lenght....ok...its tuned to a natural fraction...a harmonic....call its gain 1 dB...the only problem...its braided wire.....and if you want to mount it in a particular orientation.....you have to sopport it..ie a tube etc or it would blow arround like crazy....so a ant designer uses a shorter stiff ant rod.....say 10/12 inches....but is in itsself not a natural harmonic....by its self the gain would be some negative number over the original....so the designer attaches a coil of wire in series with his short stiff ant.....usually at the base....thus loading his short ant back into a natural harmonic....a base loaded whip......however the coil is not!!! an amplifer....its over all gain is not as good as original long wire assuming you could orrient both the same....the whip prob has a 1/2 -1dB lost over original....they advantage Wayne...is that you can mount whip....straight up/down/sideways away from electrically noisy components....but your not doing that!!!you hate the look as i do....so your going to lay the thing in most convenence spot....4 in away from reciever/power expander...oriented parallel to fuse and all the other stuff running same way....cf/servo wires/power/ecf lines etc...but you are doing it with a degraded ant.....as far as range check goes if you took the time to mount both ant ...alligned the same way...i gurantee you the range with original wire will be greater then whip as you described.....will it work...probably...you wont notice the difference.....until something really noisy comes allong like a smoke pump w/ dirty brushes....see digitech 's sad demise of airworld L39....off soapbox.....kp couch

CF is electrically conductive and as such acts the same a piece of wire.

Try it, use a bulb a battery and a piece of CF.

Any piece of wire running parallel to another will pickup the signal of the other, this can be rx output to the servo's or motor noise from pumps etc. It also acts a sort of 'faraday cage' (not a true one i know) but the effect is similar so signal strength is reduced when it passes through it.

It may be that in ideal conditions with a very strong tx signal the system will work satisfactorily but when other thing conspire against you (low level, far away other txs on adjacent frequencies, external spurious noise etc.) the weaker signal causes a lockout.

I have had very bad experiences with CF causing loss of range and would NEVER use an Ariel inside a CF fuselage.

Just recently a well known model builder in the UK who builds perfect scale models decided not to put an external Ariel (he had always done so before) he range tested and all seemed well. Many flights later out of the blue he had a lock out that cost the model.
There is no definite evidence that it was caused by the internal Ariel but the replacement model (same type) has an external Ariel and has had no problem (same radio).

In the early days of turbines in Europe Ariel were put inside the fuselage (as per DF) but many planes crashed (all with lock outs) since we all (or most) went to whip Ariel’s the problem has all but gone away.

In my opinion there is enough doubt to be cautious with you expensive jet and anything you can get in your favour you should do.

Paul

The only true way for you to know if you can mount your antenna inside your jet is to try it! Place the antenna exactly where you would like it, and then do a Real good range check...baseline and power on! Then place the same antenna outside or in a similar manor and location, as it would be mounted outside. Do the exact same range check and note the differences if any in distances. By the time you finish this process you will know for sure how and where you can mount the antenna.

Note a neat way of mounting the loaded type antenna is to place it in the nose of the plane. I've got a friend that mounts his in the nose and sticks about 3 to four inches straight out the nose! Looks fine with a portion of antenna then sticking out front far away from the ECU / pump & RFI.
Lee